Numerous azetidine compounds are known in the art and are credited with a spectrum of utilities. One such use derives from the relationship between azetidine and ethylenimine. The alkylating action evidenced by both of these compounds, and the effectiveness of the latter in various therapeutic schemes, has stimulated substantial investigation of azetidine analogs of ethylenimine derivatives of known clinical use for the control of neoplastic disease.
Azetidine compounds have also been successful as reagents in the well-known Vilsmeier-Haack reaction. There, it is azetidine amides which have been utilized.
The foregoing and other investigations have, however, been severely hampered by the low number of azetidine compounds available in the prior art. This scarcity is in turn dependent upon the prior art methods for producing such compounds. These methods permit the synthesis of relatively few azetidine compounds.
One such prior art method for producing azetidine compounds involves cyclization of amino-esters by treatment with a Grignard reagent to yield azetidinones (.beta.-lactams) which may then be reduced with lithium aluminum hydride to yield the azetidine. This reaction has been successful, however, only where the amino-ester is limited in its substituents. Consequently it has not proven useful for the production of many desired compounds.